Once these are set, restart Docky. Docky will now disallow dragging (or removing) icons from the dock, have no way to add items to the dock and have no way of accessing the settings dialog!

Please note that some docklets might expose their own settings dialogs/configuration via their popup menus (GMail, Weather, NPR, Clock, etc). Also some docklets will let you modify the system state (NetworkManager, Session, etc). You might want to think hard about each docklet you add to a kiosk environment!